In 1861, the physicist James Clerk Maxwell announced his discovery of the three-colour process on which the technology of colour photography is still based. To mark the anniversary, New Scientist looks at the inventors, tinkerers and pioneers who made colour photography possible.

The theoretical foundation of colour photography was laid in 1861. In a lecture at the Royal Society in London, the physicist and mathematician James Clerk Maxwell showed that it was possible to recreate all the colours in nature by combining red, green and blue.

He demonstrated the idea by taking three black-and-white transparencies of a tartan ribbon through red, green and blue filters. He then superimposed these three images using three projectors – each with a filter of the respective colour.

The result was a full-colour image. The image above reproduces the effect, but was produced later. Maxwell's additive colour synthesis technique is the basis behind much of photography and printing today.